1. Field of the Invention
The present invention relates generally to receivers which can be used for digital radio communication systems or sonar detection systems, and more specifically to a decision feedback equalizer with an array of antennas, or sensors for canceling multipath components of a signal received via time-varying multipath-fading channels.
2. Description of the Related Art
The combined use of art array of spaced antennas, or sensors with a decision feedback equalizer for canceling multipath-fading related intersymbol interference is known, as shown and described in EP-A 604, 956, published on Jan. 6, 1994. Using the well known least mean square (LMS) algorithm, the main lobe of the antennas is oriented in the arrival direction of a target signal, while forming a null in the direction of an undesired signal. However, if multipath components are arriving through very long return paths, their delay times are likely to exceed the length of the upped-delay line of the equalizer, and hence no equalization would result at ill. In particular, as the data transmission speed of a channel grows faster, the delay profile of the transmitted signal normalized by modulation speed extends, increasing the severity of the problem.